Effect of digital limiter-discriminator-integrator based IF detectors on the Bluetooth cell coverage

It has been widely accepted that digital limiter-discriminator-integrator (LDI) detectors operating at an appropriately chosen intermediate frequency (IF) allow the realization of inexpensive receivers for digital frequency modulation (FM), like GFSK (Gaussian frequency shift keying) modulation, used in Bluetooth. The authors found that maximum-likelihood (ML) symbol-by-symbol postprocessing applied to such digital LDI detectors yields a favorable bit error ratio (BER) performance. The novel detectors were termed max-log-ML (MLM)-LDI detectors. The paper presents a Bluetooth coverage analysis, considering both ideal and realistic MLM-LDI implementations. The coverage analysis is done for indoor office environments, taking into account the selection procedures for choosing UMTS (Universal Mobile Telecommunications System) radio transmission technologies. It is shown that the application of the novel MLM-LDI detectors in Bluetooth receivers lends itself to complying with the Bluetooth range requirement of at least 10 m with a transmit power of 1 mW, even at a coverage probability of at least 97.5% at the cell boundary.